The following situations often happen in true life of mobile phone users:
(1) Users are required to leave their mobile phones in sleep mode (that is to say, the mobile phones cannot receive or send any message and the current solution is to switch the phones off) when on a plane; and they need to awake their mobile phones when off the plane (the current solution is to switch the phones on).
(2) Users prefer to leave their mobile phones in sleep mode and have a secretary service handle calls when listening to an academic report; when the report is finished, they need to awake their mobile phones.
(3) Users like to inform their family when they arrive at or leave a hotel.
(4) Users like to transfer calls to family phones when at home or to office phones when in the office.
(5) Users set alarm clock at 7 A.M. to wake them up at home, and at 2 P.M. to wake them to resume work after having a nod in the office.
Nevertheless, how could a mobile phone distinguish these situations by itself, and then make corresponding responses at a user's wishes? For example, the mobile phone shuts down the RF module initiatively and remains in sleep mode when the user is on the plane, and opens the RF module and awakes itself when the user is off the plane.